Benzo(beta)pyrylium dye salts

ABSTRACT

A CLASS OF NOVEL BENZO(B)PYRYLIUM DYE SALTS HAVING A PARTIALLY SATURATED, BICYCLIC RING SYSTEM FUSED THERETO IS DESCRIBED.

United States Patent Office 3,745,176 Patented July 10, 1973 US. Cl. 260-335 3 Claims ABSTRACT OF THE DISCLOSURE A class of novel benzo[b]pyrylium dye salts having a partially saturated, bicyclic ring system fused thereto is described.

This is a divisional of application Ser. No. 15,832, filed Mar. 2, 1970, now US. Pat. No. 3,694,462.

This invention relates to a novel class of benzo[b]pyrylium dye salts and in particular to such dyes having a partially saturated, bicyclic ring system fused thereto.

Compounds of the hereinafter described benzo [b] pyrylium dye salts with partially saturated bicyclic ring systems fused thereto are more rigid in configuration than pyrylium dyes not containing this fused configuration. Such dye salts have a utility for sensitization of photoconductors and electrophotographic systems, as well as for other light sensitive systems. Further such dyes are unusually well suited for dye laser applications.

It is therefore an object of this invention to provide novel pyrylium dyes as hereinafter described having the sensitizing and lasing ability mentioned.

The compounds of the present invention have a structure conforming to the following general formula:

wherein R is a hydrogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkyl group having 1 to 12 carbon atoms, or a dialkylamino group wherein each alkyl substituent of the dialkylamino group has 1 to 4 carbon atoms; R R R and R are each a hydrogen atom or one of the pairs of groups R and R R and R or R and R are taken together to be a 1,3-butadienylene group while the remaining R R R and R groups are hydrogen atoms; n is an integer from 1 t0 4; and X is an acid anion such as halide, perchlorate, tetrafluoroborate, sulfate, bromate, carbonate, periodate, alkylsulfonate, arylsulfonate, and the like.

Compounds having the hereinbefore described general formula can be prepared by the reaction of an orthohydroxy aromatic aldehyde with a cyclic benzo ketone in the presence of acetic acid and a stream of hydrogen chloride gas. Generally, perchlorate acid is also added to the reaction mixture to facilitate isolation of the reaction product as the perchlorate salt which precipitates from the reaction product as the perchlorate salt which precipitates from the reaction mixture. The general preparation is illustrated by the following reaction on n R i) j O QJQ 1 010,

In a typical preparation the mixture of 0.1 mole of an orthohydroxy aromatic aldehyde, 0.1 mole of cyclic ketone, 100 ml. of acetic acid and 25 ml. of solution of perchloric acid are warmed on a steambath for about 30 minutes while bubbling a stream of dry hydrogen chloride gas through the reaction mixture. The mixture is cooled and the precipitated product isolated by filtration and then recrystallization from acetic acid, acetonitrile or mixtures of the two. The following examples i1- lustrate specific preparations of compounds of the present invention using the hereinbefore described reaction procedure.

EXAMPLE 1 12,13-dihydro 10 methoxy-dibenzo[a,h]xanthylium perchlorate having the following structure e O/ 0104 CHaO is prepared by mixing 0.1 mole of 2-hydroxy-l-naphthaldehyde with 0.1 mole of 6-methoxy-1-tetralone. The product was recrystallized from acetonitrile in a 42% yield at a melting point range of 272 C. to 275 C. The elemental analysis comparing the calculated amounts/ amounts found, showed the following: C, 64.0/64.4; H, 4.1/4.4; Cl, 8.6/8.5.

3 EXAMPLE 2 lO-methoxy 12H indeno[3,2-b]-naphtho[1,2-e]pyrylium perchlorate having the following structure is prepared by mixing 0.1 mole of 2-hydroxy-1-naphthalhehyde with 0.1 mole of S-methoxy-l-indanone. The product was recrystallized from acetic acid in a 55% yield at a melting point range of 283 C. to 285 C. The elemental analysis comparing the calculated amounts/ amounts found, showed the following: C, 632/629; H, 3.8/4.1; Cl, 8.9/9.1.

EXAMPLE 3 1,2 dihydro 4 methoxy-benzo[c]xanthylium perchlorate having the following structure is prepared by mixing 0.1 mole of salicylaldehyde with 0.1 mole of 6-methoxy-1-tetralone. The product was recrystallized from acetonitrile in an 85% yield at a melting point range of 245 C.

EXAMPLE 4 Benzocyclohept[5,4-b] naphtho[1,2-e]pyrylium perchlorate having the following structure OCH:

EXAMPLE 12H-indeno 3,2-b] naphtho- 1,2-e] pyrylium perchlorate having the general structure 53 (not is prepared by mixing 0.1 mole of 2-hydroxy-1-naphthaldehyde with 0.1 mole of l-indanone. The product was recrystallized from acetonitrile/acetic acid 1:1 in an 82% yield at a melting point range of greater than 300 C. The elemental analysis comparing the calculated amounts/ amounts found, showed the following: C, 65.2/65.0; H, 3.5/3.7; Cl, 9.6/9.8.

EXlAMPLE 6 12,13-dihydrodibenzo[a,h]-xanthylium perchlorate having the general structure 8 methoxy-IOH-indeno-[2,3-e]benzo[b1pyrylium perchlorate having the general structure CHzO is prepared by mixing 0.1 mole of salicyaldehyde with 0.1 mole of S-methoxy-l-indanone. The product was recrystallized from acetonitrile in a 72%, yield at a melting point range of 244 C. to 245 C. The elemental analysis comparing the calculated amounts/amounts found, showed the following: C, 58.5/58.2; H, 3.8/4.0; Cl, 10.2/10.1.

The hereinbefore described class of compounds are useful as sensitizers for electrophotographic systems as demonstrated by the following results.

The compound of Example 2, 10-methoxy-12H-indeno- [3,2-b]naphtho[1,2-e]pyrylium perchlorate and the compound of Example 3, 1,2-dihydro-4-methoxy-benzo [c] xanthylium perchlorate were used to sensitize photoconductive coatings containing triphenylamine and 4,4'-bis- (diphenylamino)chalcone respectively. The following table indicates that the photoconductors in conjunction with the compounds in a Vitel PElOl, a polyester resin sold by the Goodyear Tire Company comprising poly- (4,4' isopropylidene-bis-phenyleneoxyethylene-co-ethylene terephthalate), matrix produce photoconductive compositions having useful electrical H and D shoulder and toe speeds. The Vitel binder is generally used with 20% by weight of the photoconductor and 0.8% by weight of sensitizer compound.

Further explanation of significance of the electrical H and D speeds can be found by reference to the explana- 6 tion in U.S. Pat. 3,449,658, Robinson et a1., issued June References Cit d 10, 1969- FOREIGN PATENTS Utility of these compounds as lasers is described in c0 pending US. application Ser. No. 15,489 filed Mar. 2, 181,096 5/1966 73; y 53 i s qt d d t OTHER REFERENCES e mven 1011 as een escn e 1n e a1 Wl particular reference to preferred embodiments thereof, but Jean Andneux et Acad' Pans 271C it will be understood that variations and modifications (July 1970) can be effected within the spirit and scope of the invention. Dorofeenko et Tetrahedron, 1966,

What is claimed is: 10 PP- 23 PP- 1. 12,13 dihydro-10-methoxy-dibenzo[a,h]xanthylium perchlorate. NORMA S. MILESTONE, Primary Examiner 2. 1,2-dihydro 4 methoxy-benzo[c]xanthylium perchlorate. US. Cl. X.R.

3. 12,13-dihydrodibenzo[a,h]xanthy1ium perchlorate. 15 260-3453; 252-501; 96-89 

